Method of making oxidatively stable water soluble amorphous hydrated metal oxide sized fibers

Abstract

A method of making a polymeric composite wherein the polymeric composite is more oxidatively stable. The method comprises reacting aluminum, titanium, silicon, or zirconium with HBr or HI 2 , oxidizing the reaction product to form a hydrosol and applying the hydrosol to the fiber surface prior to incorporation in a polymeric composite. The composite exhibits greater oxidative stability as it is exposed to temperatures of about 100° C. to about 900° C.

I claim: 
     
       1. A method of making a fiber reinforced polymeric matrix composite material wherein the fiber reinforcement has a layer thereon formed by (a) reacting aluminum, titanium, silicon, or zirconium with HBr or HI;   (b) oxidizing the reaction product with a water soluble oxidizing agent to form a hydrosol and reduce the anion concentration; and   (c) applying said hydrosol to said fiber surface.   
     
     
       2. The method as recited in claim 1 wherein the reacting metal is selected from the group consisting of titanrum, aluminum, and silicon and the fiber is selected from the group consisting of graphite, glass, silicon carbide, alumina, boron and polyaramid. 
     
     
       3. The method as recited in claim 1 wherein the fiber is graphite and the reacting metal is aluminum. 
     
     
       4. The method as recited in claim wherein said oxidized reaction product is dialyzed. 
     
     
       5. A method of using a fiber reinforced polymeric matrix composite material wherein the fiber reinforcement has a layer thereon by exposing the composite to temperatures of about 100° C. to about 900° C. wherein the improvement comprises forming said layer by: (a) reacting aluminum titanium, silicon or zirconium with HBr or HI;   (b) oxidizing the reaction product with a water soluble oxidizing agent to form a hydrosol; and   (c) applying said hydrosol to said fiber surface; wherein the composite has greater oxidative stability.     
     
     
       6. The method as recited in claim 5 wherein the reacting metal is selected from the group consisting of titanium, aluminum, and silicon and the fiber is selected from the group consisting of graphite, glass, silicon carbide, alumina, boron and polyaramid. 
     
     
       7. The method as recited in claim 5 wherein the fiber is graphite and the reacting metal is aluminum. 
     
     
       8. The method as recited in claim 1 wherein the composite is exposed to temperatures of about 500° C. to about 900° C.